Vote for your favorite songs, albums, artist, music videos and moments of 2015's first half!

In one week, 2015 will be halfway done -- and a fantastic year of popular music will already be in the books. From Taylor Swift's unstoppable radio run to Sam Smith's huge Grammys night to the One Direction lineup shakeup to Madonna's latest eye-popping music video, this year has been host to some musical moments that will resonate long after the year ends. Now, it's your turn to sound off on the most unforgettable pieces of pop over the past six months.

With the first half of 2015 nearly complete, cast your vote now in the fifth annual Billboard.com Mid-Year Readers' Poll to tell us what artists, songs, albums, videos, tours and fashion choices have defined this year. Which Hot 100 Top 5 smash was your go-to jam? What single moment was the most buzzed-about of 2015? And which new artist do you think enjoyed the biggest breakout? We've offered a few suggestions for each category, but feel free to write in a candidate.

Vote now in the 2015 Mid-Year Readers' Poll, and we'll announce all of the winners at the end of the week (June 26) on Billboard.com!